From the author blog:
Showdown is a roleplaying game about two people who are locked in a struggle that can only end with the death of one of them. It’s for two players and should take between 60 and 90 minutes to play. Over the course of play, you and your opponent will be fighting over two things: the outcome of a climactic duel between these two foes and the history that led them to that duel. Win the duel, and you get to choose who lives and who dies. Control the history, and you get to shape why they fought in the first place. How did it come to this? Who’s the hero? Who’s the villain? And who’s standing when the dust settles?